Relations between mood characteristics, circadian preferences, and functionality in multiple sclerosis

Objective. Multiple sclerosis (MS) is a progressive disorder that results in demyelinization of the nerve fibers of the central nervous system. We aimed to determine chronobiological and mood features in patients with MS. Methods. The sample comprised 75 patients with MS (54 women and 21 men) and 50 healthy individuals (38 women and 12 men). Sixty-three patients were relapsing - remitting MS and twelve patients had secondary progressive-type MS. Mood characteristics were assessed using subscales of the Profile of Mood States (POMS). Chronotypical characteristics were determined by the Morningness-Eveningness Questionnaire (MEQ). Univariate and structural equation modeling was applied to untangle the possible connections between variables. Results. Both relapsing - remitting and secondary progressive patients scored higher on the depression - dejection and fatigue - inertia scales of the POMS than healthy individuals. Circadian preferences did not differ significantly between these groups. Patients using glatiramer acetate and other types of drugs had greater severity of functional impairment measured relative to interferon-beta treatment group. Glatiramer acetate had more negative effects on mood than interferon-beta therapy. This finding may be the result of significantly higher duration of disease and higher symptom severity scores in glatiramer acetate group. Conclusions. In the structural equation model, gender was found to be predictive for characteristics of mood.